## NS FL 3 B/BC Q2

apple
Posts: 2
Joined: Mon Apr 16, 2018 12:23 pm

### NS FL 3 B/BC Q2

Hi guys,
I was working through NS test 3, and I did not understand the answer explanation for question 2 on the bio section.

Could someone work out the calculation for the answer step by step?

Thank you!
Attachments
Screen Shot 2018-04-16 at 12.25.45 PM.png
NS_Tutor_Andrew
Posts: 520
Joined: Mon May 23, 2016 1:47 pm

### Re: NS FL 3 B/BC Q2

Hi apple,

Thanks for the question! To be honest, I think the explanation is a little bit more detailed than it needs to be, because it calculates the odds of various genotypes and then assesses which are viable. However, the question gives us info about the rate of viable births, and asks about the likelihood of viable births, so we don't really need to re-do that work. We can just estimate that 1/130 will be between 1% (=1/100) and 0.5% (=1/200) [and closer to 1% than 0.5%] and subtract that from 100%, so we know that we're looking for something between 99.5% and 100%, which is A.

Hope this helps & please feel free to reach out with more questions!
Andrew D.
Content Manager, Next Step Test Prep.